A refrigerator is an apparatus aimed at storing foods at low temperature, and may store foods in a frozen or refrigerated state according to the type of food intended to be stored.
The refrigerator typically has a rectangular main body which is open at a front surface thereof. The main body section may have storage chambers, namely, a refrigerating chamber or compartment and a freezing chamber or compartment, therein. The front surface of the main body section may be provided with a refrigerating chamber door section and a freezing chamber door section, for selectively closing the respective portion. The refrigerator may include a plurality of drawers, shelves, and storage boxes, etc., in order to optimally store various foods in an internal storage space of the refrigerator.
The refrigerator includes a cooling cycle section or system for generation of cold air that is supplied to each storage chamber. The cooling cycle section may include a compressor which compresses a gas-phase refrigerant at high temperature and high pressure, a condenser which condenses the gas-phase refrigerant compressed by the compressor into a liquid-phase refrigerant, a capillary tube which changes the liquefied refrigerant into a low-temperature and low-pressure refrigerant, and an evaporator which cools ambient air by absorbing the latent heat of vaporization in order to evaporate the refrigerant liquefied at low temperature and low pressure by the capillary tube.
In more detail, the evaporator typically has a lower surface temperature than the temperature of air in the storage chamber. Thus, moisture present in the air in the storage chamber may be changed into frost and the frost may adhere to the surface of the evaporator. This frost causes a decrease in the heat exchange capability of the evaporator.
In order to remove the frost, the refrigerator may include a defrost section (defrost unit) such as an electric heater. The defrost section is operated when the frost needs to be removed, and the defrost section is not operated, but is stopped, when the storage chamber needs to be cooled. In this case, the operation and stoppage of the defrost section are repeated depending on the length of a predetermined defrost period.
The refrigerator may be operated in a power-saving mode (e.g., a low power consumption mode) introduced according to, for example, energy consumption regulations. The power-saving mode is an operation mode in which less power is consumed than usual. Accordingly, the defrost period in the power-saving mode (for instance, 48 hours or 72 hours) may be longer than a defrost period in an operation mode other than the power-saving mode (for instance, 8 hours) (hereinafter, the operation mode other than the power-saving mode is referred to as “normal mode”). The storage chamber (or the interior of the refrigerator) in the power-saving mode may have a higher temperature than that of the storage chamber in the normal mode. In addition, the compressor (inverter compressor) in the power-saving mode may have a lower rotation speed than that of the compressor in the normal mode.
However, when one or more of the following situations (hereinafter, referred to as an “abnormality”) occurs in the power-saving mode, then the defrost period in the power-saving mode may cause an excessive amount of frost to accumulate (e.g., excessive adhesion of frost). For example, when opening of each door section is not detected due to failure of a door section sensor and warmer air is introduced through the door section, when minute opening of the door section is not detected by the door section sensor and warmer air is introduced through the door section, when a great quantity of frost is already present before the refrigerator is operated in the power-saving mode, or when a user uses only the freezing chamber (a user opens and closes only the freezing chamber door section) in a refrigerator in which the door section sensor is provided only in the refrigerating chamber, then the defrosting is performed in the defrost period in the power-saving mode even though the defrosting should be performed in a shorter period than the defrost period in the power-saving mode. For this reason, heat exchange degradation may result due to the excessive adhesion of frost.
Therefore, a technology for preventing the excessive adhesion of frost caused by an abnormality that occurs when in the power-saving mode would be valuable.